Earlier quoted context omitted.
The specification you present is a bit unclear. Any modern virtualization has very fast CPU virtualization (it's hard to say near-native, as there are always corner cases), and snapshotting tools. I don't know about Sharepoint; the "clone installs" is a bit fuzzy too, but one can clone installed systems by just copying the underlying image file and ensuring that it has a unique identifier (and updating the guest O/S…
For the USB part, would adding a extra USB adaptor card (assuming it's a desktop machine) and using PCI-passthrough/VFIO on that adaptor make it easier? From my knowledge of QEMU, then no USB emulation is involved - the guest OS sees the entire USB adaptor (and the host doesn't) - so one can have all the special USB hardware connected to that.
What needs to be kept in mind is that, as the standanrd passthrough, it's subject to the IOMMU groups handling (in best case, there's no other device in the same group; otherwise, one needs some trickery, which AFAIK is not 100% guaranteed to work).